Home Theater

TV Viewing Distance and Screen Placement in the Home Theater

The optimal television screen size is completely related to the presented watching distance.  Nevertheless, there are additional concerns as well that has to be taken into account.

Viewing Distance: Is it only a subject of individual liking?

Sit extremely near your large screen television and you will be able to see the picture build-up structure – scanning lines or pixels forming the image, thus disturbing your attention and spoiling your home theater experience. Nevertheless, stay too far away, and the impression will be lost.

The truth is that there aren’t any scientific rules here. This does not denote that there aren’t any guidelines that you need to go by when preparing for a extensive screen purchase or a possible home theater room.

SMPTE Recommendations and the THX Certification standards:

The Society of Motion Pictures and Television Engineers (SMPTE) commends that the screen dimension for home theater use has to occupy a 30 degrees area of view – in the horizontal arrangement – for the watchers. Alternatively, the ideal TV watching distance should be such that the screen width occupies an angle of 30 degrees from the watching place.

This SMPTE principle is also in proportion to the THX certification standards in that these suggest that the backside row of seats ought to have at least a 26 degrees watching angle and while proposing a most advantageous viewing angle of 36 degrees.

So How Does All This Translate In Practical Terms?

A general rule for the television watching distance according to the SMPTE and visual perspicacity guidelines, is that the nearest TV watching distance between you and your big screen TV should be narrowed to about twice the screen width (more accurate 1.87 x screen width for a subtended angle of 30 degrees), while the furthest distance being not exceeding five times the width of your screen.

Nonetheless, it is also important to understand that these maximum and minimum watching distances ought to be seen in the light of the video signal definition.

A totally resolved high definition television (1080i, 1920×1080) supports a closer viewing distance than regular analog television. While two times the screen width would be the best television viewing distance for a HDTV display, it will be a bit too close for customary television; in the later case, a thrice the screen width will be a superior alternative.

When it speaking about the use of regular-size standard definition analog TVs in the home theater, i.e. around 36 / 40 diagonal, the best watching distance range is between 8 feet and 12 feet. TV sets smaller than 36-inches are not big enough to meet the criteria for Home Theater utilization for the reason that their tinier screen dimension will not grant the expected impact on the viewer.

Vertical Angle of View & Screen Height:

For best viewing, the eyes of the viewer must be at the same height as the focuse of the screen.

Maximum vertical angle of view: In those home theater set-ups where this isn’t likely, the SMPTE principles suggest that the maximum vertical angle estimated at the seated eye height from the front row middle location to the top most segment of the projected image should not surpass 35 degrees.

This doesn’t stand for the optimal watching angle but rather the constraint beyond which the watcher will be exposed to a heightened neck tension.

Minimum angle of vision: While there do not seem to be any limited SMPTE or THX guidelines in this aspect, investigations have presented that if the screen dimension occupies below 15 degrees of the watcher’s vertical field of view, then that picture looks as if it were miniature.

Practical Considerations:

In a typical home theater set-up, you do not have to really fret on neither the maximum vertical angle of view, nor concerning the minimum vertical angle of vision for an effectual movie theater experience.

If one were to adhere to the commended TV watching distance of twice the screen width (as additionally explained previously based on the SMPTE principle of 30 degrees horizontal field of vision), you would necessarily be complying with the least possible angle of vision. The grounds behind that is there’s a set relationship between screen height and width in accordance to your home theater screen aspect ratio of either 16:9 or 4:3.

Keeping in mind that most home theater rooms are almost 10 feet (3m) high, the resulting vertical viewing angle is typical well within the maximum of 35 degrees detailed in the SMPTE guidelines, all you need to do is just remain within the double the screen width guideline for your viewing distance.

If you would like to read more about this topic go to this Tech Blog.

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